Automatic device for draining variable-pressure alarm systems



Oct. 27, 1925- 1,558,623 H. w. PARK AUTOMATIC DEVICE FOR DRAINING VARIABLE PRESSURE ALARM SYSTEMS ed Dec. 3l, 1921 m Tn m m m mss swme; diaz/nt,

Patented Oct. 27, 1925.

UNITED STATES PATENT OFFICE.

HALFORD W. PARK, O'F SCARSDALE, NEW YORK, A'SSIGNOR TO ROCKWOODSPRINKLER COMPANY 0F MASSACHUSETTS, OF WORCESTER, MASSACHUSETTS, A CORPORATION 0F MASSACHUSETTS.

AUTOMATIC DEVICE FOR DRAINING VARIABLE-PRESSURE ALARM SYSTEMS.

Application filed December 3l,` 1921. Serial No. 526,427.

To all whom t may conce/1%.'

Be it known that l, HaLronD W. PARK, a citizen of the United States, residing at Scarsdale, in the county of Westchester and State of New York, have invented a new and useful Automatic Device for Draining Variable-Pressure Alarm Systems, of Which the following is a specification.

This invention relates to an automatic device for controlling the supply and discharge of Water under pressure for operating an alarm or the lik The principal objects of the inventionv are to provide means which will insure. that when the alarm valve check lifts from its seat all the Water discharged through the pipe and spaces connecting the annular port of the alarm valve With the alarm actuating mechanism will be utilized for alarm purposes without waste, and to provide means which vvill insure that When the check closes,y the Water thereby left trapped in the alarm valve system Will be drained forthwith leaving the alarm valve connecting pipe and r spaces in their normally empty condition and thus automatically7 ready for further operation; to provide a construction in which, although both of the above objects are attained, no alarm Will result from the uncovering of the annular port as the effect of mere ivater hammers transmitted to the alarm valve through the yWater in the system; to provide a system in which there are no moving parts except a float valve, nothing` to create friction and nothing to corrode; and to provide these features in such form' as to be practically applicable to a fire sprinkler system.

`Further objects and advantages 'of the invention will appear hereinafter.

Reference is to be had to the accompanying drawings, in Which Fig. 1 is a longitudinal central sectional vieiv of a part of a sprinkler system showing' a prefered form of this invention applied thereto, and

Fig. 2 is an end view of the retarding chamber and controlling device.

I have shown the invention as used in connection With a variable pressure alarm or check valve 10, in this instance used in connection with a Water main 11 under high pressure and a stand pipe 12 to Which the various sprinkler heads are connected.

Zhen the valve 10 opens, either on account of reduction 1n the pressure above it, or for any other reason, `Water will flovv as usual through a pipe 13, the `end of which is connected with an annular `port in the valve seat which is normally closed by the valve 10. The pipe 13 is shown as feeding through a passage or other conduit 15, in the usual Way, into a retarding chamber 16. This chamber is connected by a pipe 17 With a Water motor alarm device 9, located at any desired place and adapted to be operated by the flow of Water from the retarding chamber to sound an alarm. The parts so far described are of the usual construction and serve the usual purposes. This invention does not need to be used With a retarding chamber, as it can serve for retarding pur poses itself to prevent sounding' of the alarm in case of Water hammer, with modiications Within the skill of those skilled in the art.

In order to discharge the Water fromv the retarding chamber it has been customary heretofore to provide it With a constantly open drain outlet of small area which Will, of course, discharge Water all the time the retardingchamber` is beingfilled and` all the time that the alarm is operated. yIn order to secure sufficient operating pressure at the gong this drain opening has to be made small and therefore it takes a long time for the retarding chamber and connect the pipes to be drained by it after the alarm valve check 10 is closed. As stated above, this invention involves means by Which all the Water that flows by the valve check 10 through the pipe 13 Will be delivered into the retarding chamber or the alarm motor system Without Waste and When the valve 10 closes again the Water Will im'- mediately discharge from the retarding chamber into the atmosphere at a rapid rate and this discharge will continue until the .retarding chamber and connecting pipe and spaces are empty. The rapidity `vvith Which the parts are brought back to normal condi tion for operation again permits the real function of the retarding chamber to be maintained by preventing Water hammers, even if occurring in close succession from starting the alarm-to operate.

Forthese purposes I can attach the device anywhere in the pipe line between the alarm valve 101andf thewater motor 9buu I have shown itl as attachedVl to thecoverl plate 18 ot' the retarding chamber which is usually locatedv on the bottom; For that purpose l havefshown the passage as located in this l ber 23 below. ylihis exerts pressureV on a body, of heavy liquid, preferably mercury, 2i

in` the bottom of that chamber. it the bot tom this kchamber has a port 25 connecting with asuction chamber dalsolocatedin the casingQO andot` course, also having` a body ot mercury in it which, when there is no pressure, will come to the level ot the mercury in the pressure chamber 23. Floating in the mercury of the suction chamber is a float 27 which can be made of cast iron,

weighted with lead 28, ii' desired, and provided with a valve 29 at the top which preterably is formed of Monel metal. Just above this valve is a valve seat having a large drain port lSOthrough it which also can be formed ot Monel metal. This port communicates with a trap or chamber 31 in the casing 19, which in turn,v communicates with a discharge pipe or port 32 near the top ot' the trap for discharging' water from the system into thevopen air.

Also communieating` with the top ot the suction chamber 26 there is a passage 33 leading into a safety trap or chamber $11 inthe casing 19.' On the top of this there is a Pitot tube35. somewhat larger than the tube and with its curved end; turned in the opposite direction. The passage 33 is larger than the passage 21 also. but the passage in the valve seat is still larger. The bottoms ott the traps 3l and 34 slope in all directions toward their openings in the bottom to allow the mercury to'drain. out it it iiows into them.

lVhenfthe clapper. of the main alarm valve isgshut and the alarm'valvesystem is drained there is. veryf little hydrostatic pressure on the. surfaces of the mercury in the two cham* bers and what there is is nearly equal, so thesevsuritaces are at substantially the same eievation. The float 27 therefore remains in its ylowest position leaving the vent hole 30 open to the atmosphere..` Whenever the valve. 10 opens and the water starts to :flow intoy the retarding chamber, the action of this flow 'of water. unbalancesthe pressure in the two chambers 23 and 2GA in two ways. Pressure is exerted in the chamber 23 by the head` due to the velocity of water past the Pitot tube and suction is created in the. chamber 26 bythe flow ofithewater past the other Pitot tube 35. The first of these can be made sufficient to close the valve 29 but lf prefer to.. rely on the two together. The pressure chamber 23 being closed. and

lthe suction chamber 2d being open to the vtheretorepo the Fit'ot tube 35, there are two forces acting to close the valve 29, first, the hydrostati'chead assoon as any water is received in the retarding chamber, and

second, the pressure due to the velocity head due to the water flowing through endl past the tube lEither ythe diiterence inthe pressure due to the hydrostatic head alone or lthe difference in pressure due to velocity alone will cause the float to rise. The float ha vingonce risen, the pressure due to hydrostatic head in the two chambers becomes baieuncedv because there is no outlet and therefore the only pressure lett to hold the valve closed is that due to the velocity of the wat-er flowing past the tubes 22 and 35, plus the unbalanced hydrostatic head'on area of the vaive equal to the area olf the port 30. It it were not for the Pitot tubes, therefore, or at least one of them, the iioat would i'all baol; from the vent hole. It is chieily the diiiierence in velocity pressure due to these two tubesthat holds the float onits seat while the water is owing.

Just as soon as the water flow stops, this difference in velocityv head also disappears and as the hydrostatic head on the two chambers is already equal, the mercury returns Ato the original equal. levels in the two chambers and the valve :29 opens by gravity, coming` down into the position shown in F ig. 1. Now, the water is free to drain out through the port 30 as rapidly as it went into the retarding chamber and thus the device is restored to its set condition ready to operate when the valve 10 opens again. l

The vent hole receives and discharges its water into the safety trap 31 which is large enough to contain all the mercury in the pressure chamber that cannot be contained in the suction chamber when the iioat is up to its valve seat. rl`he drain 32 leads from near the top ot this chamber 31. This safety chamber is designed to guard against. any possibility of 1ross ot' mercury through the drain pipe it the valve should not seat perfectly and it the d'iiierence in velocity head under heavy pressures should be great enough to litt the mercury over the float through the` vent lio-le.

Thesatety trap or chamber 311' is provided to guard against any similar loss ot mercury through this passage into thepiiowpipe.

lBO

There being only a very small velocity of water through these safety chambers'it is impossible for any mercury to escape. The bottoms `of these chambers are sloped toward their inlets at the bottom so that as soon as the pressure is relieved any mercury that might have gathered in them runs back to its proper place in the suction cha1nber. It is to be observed that no matter how great the velocity of water becomes due to seat continually increases until the maXimum torce is obtained when the retarding chamber and the pipe to the water motor nozzle are completely lled. Ii there should be a slight leak around the valve 29 while the float is seated it would not affect the operation o the alarm. It is to be noted that there are no moving parts in the device except the float and nothing to present any friction or to make it possible for the parts to corrode or fail to operate. It depends solely and directly upon the laws of hydrostatics.

Although I have illustrated and described only a single :form of the invention, I am aware of the fact that modifications can be between the alarm valve and the water motor nozzle and connected with said passage, a valve adapted to completely close said outlet, and means for causing the pressure due to the flow of water through the system tol act on the valve to close it, whereby the valve will open as soon as the ,water stops flowing.

2. In a water alarm system, the combination with the main alarm valve, a water motor alarm, means for conducting water under pressure from the main to the water motor when the alarm valve opens, a drain outlet port for the water in the system, a separate passage from said means to said port and a valve controlling the ow of water through said port7 oit means whereby the last named valve will tend to remain closed whenever the water lows in the direction from the alarm valve to the water motor and the valve will be forced against said seat by the pressure caused by the flow ot' water, and whereby it will alsov be held against the seat by the hydrostatic head ot water in the system.y said valve being ar ranged and adapted to recede from its seat as soon as the pressure due to the iiow of water stops.

3. In an automatic alarm valve system, the combination with a main allarm valve, a water motor ala-rm, and a conduit controlled by the main valve tor conducting water from the riser to the motor when the alarm valve opens, of a discharge port, an upwardly opening port for discharging the water from the system into said discharge port, a valve below it adapted to close the port from below, and means whereby said valve is held up in opposition to its weight against the valve seat to close it by the force of the water flowing through the system from the riserto the water motorl and whereby when it becomes seated the hydrostatic head {of wiater above it willi assist in holding it to its seat, said valve having a weight suflicient to cause it to fall away from the seat whenever acted upon only by the hydrostatic head in the system.

4. In a device of the character described, the combination of a retarding chamber, a conduit for leading water thereto, a discharge port, a valve seat opening upwardly for discharging the water 'from said conduit into said discharge port, a chamber below the valve seat, an upwardly operating valve in said chamber having a weight sufficient to cause it to drop away from the seats when held to it by nothing but the hydrostatic head above it in said retarding chamber and system, and means whereby the flow of water along said conduit toward the retarding chamber will exert pressure below said valve to force it up against the valve seat and whereby when it has once closed, the hydrostatic head will also assist in holding it against the seat.

5. In a device of the character described, thecombination with an alarm motor and a conduit for conducting water thereto,'of a Pitot tube projecting into said conduit and having its curved admission end extending toward the source of pressure in the conduit, two chambers below the conduit one communciating with said tube, the other chamber having an outlet port at the top and communicating with the conduit, a valve in the second chamber adapted to rise therein and close the port, and means connecting said chambers for transmitting the pressure lill) las dfe to theveloeityk oilY Water'pastthe Pitot tube to saidy Valve l to 'cause fit; to ybeelevated andvv l' seated.

6: Inafdeviceoatthe character described;v

the f combination vWi-tha retardingvchamber and" al con'duit'or- :conducting Water thereto,

oit apairf ot 'Pitot vtubes ext-ending ,from saidconduit and projectingyintoit" in opposite directions, two chambers below'the :cond-{litteach eoinnnmrcatmg with one et* said tubes,v

one of said chambers eonstitutinglapressure cha/nher,i the Pitot -tube communicating with;

which has its curved admission-end extendL ing toward lthe source of pressure intheconduit,y the other chamber having anoutlet opening at the top and*communicating- Withthe other Pitot tube, a Hoet valve in they secondlohaniber adapt-ed to rise therein an d f close the potty-and a body et heavf,Y liquidv inthevbottoms of the two chambers'which communicate with each other.

7. In a devicefoi"rk the. character described,y

the Combination With a retarding chamber and-ar conduit for conducting Weten thereto,y of'a Pitotltubefextending from said conduttand projecting` into it7 two chambers below the conduit,` the Pitot tube\communmatingy with one of said chambersand having 'its curvedk admission end extending towardithe" source of pressure in the' conduit, 'the' other chamber having an outlet opening at 'the' topandcomnitmicating With-the conduit, a

valve in the second chamber adapted to rise therein and close the port, and means connecting` said chambers for traiisnitting the pressure due tothe velocity of Water .past the Pitot tube to said Valve to cause it to beV seated, said mea-ns comprisinganeopen commu'nication between the twoA chambers,`

and a body of mercury?- in thebottomsetIv said chambers, on Awhich mercury 'in the' second' chamber sa'id valve 'Heats'.Y

8; ln a dev-ice ofthercharacterdescribed, the combination with a retarding. chamber and a'fconduit for' conducting),T -Water thereto,

ot a :pair of Pitot tubesI extending from said conduit and projecting. into'itinfopposite directions,l `tWo `communicating charn-y bers belen7 the conduit, each communicating Withone'ot said tubes, and having a body oi'lfheary liquid therein,4 oneof said chain;

bers constitutingv a pressure. chamber the litot tube communicating' WithWhich has curved admission endl extending I toward the retarding cha-mberfythe otherv ychamber havingran `ontlet#operaiIig-:atthe vtop and also communicating Wi'ththe other lPitotv tube,'

a valve in'lthe second' chamber` floating on theV liquid therein so astobe-adaptedfto preserve; dile U heavy liquid 4to saidvelve to cansel it to be seated, and a safety trapabovc saiddport iorretaining anyl said heavy 'liquid that Hows-finto it'and discharging.- it back in't'o the second chambenu .f

9. In a device ofthe character described, the combinatienfrwith `a retarding chamber and a conduit-for conducting-.Water thereto, el `a pair oft- Pitotl` tubes eiitendinglffrom conduit and projectjing,into it in ppo'site directions,- two-v ehambers jbeloivf the conduit each communicating with'V4 one of saidA tubes, communicating, Iwith reach otherrat' the hottomfonef of' said chambers con'stitutingv a pressure chamber and the other having` an outlet port,- a 'body ofner cury .in the two chambers, ,Valve in; the second chamber floatingson the mercury and adaptedt rise therewith yand 4close t eport', andra sa; y trap or chamber connecting Athe second chamber with ther second Pltt tube for receiving any ii'rercury that may rise aboye the second chamber vandr feeding it back by Lgravity into saidsecond chamber when the pressure isfre'm'ov'ed.

i0. In ,a device-0f 'the character descrbed,

the combination Withfa conduit of abair of chambers belowl the conduit communica-ting with'eachotherl at the bottom, one of said chambers 'constituting a pressure Vchain-ber and the other haring an outlet port,'a body of'mercury in the two'chambers, ya valx'fe in" the second vch'amber Heating yon the mercury and adaptedtofrise therewithfand cllosethe port, andgay safety ytrap or chamber con! necting the A'second chamberI for receiving tionU is produced just beyond the orifice' when water "'ws thrmigh the @enduit te the i alarml and mean s' kkwhereby i the' suction is transmitted tothe Valve 'to' close 'and' "holdI it ei'sd while the' waterjisjflowing;

YIttesti'mony; whereof l have' hereunto' affiied my' signature.' HALFOR-D V. PARK. 

